Hi
Here is a tip for you , and I own computer and laptop repair shops...
You diagnose the problem on a machine BEFORE you quote the customer... then you CANNOT lose money because even if they dont want the work done, you charge for the diagnosis....
But seeing as you are asking here... you probably need a LOT more experience before you do this for money....
Oh and ALL computers are "problematic" at one time or other, otherwise people like me wouldnt make any money and help forums like this would not exist...
Oh and its the motherboard thats faulty by the way....
All the best Brett